You need to try out some tutorials from the help menu or watch some youtube video's on using ACA.
The system is clever enough to automate what you are referring to.
I select a wall tool on a menu and click two points (like you would create a line) to create a full 3d wall. In plan view it appears 2d. In elevation or iso/perspective it is 3D with a height. It also follows the 'wall object' rules so if you used a solid wall or a cavity or componant wall it may have various componants such as external brick or stone, , moisture barrier, cavity with insulation, internal skin or brick or frame, plaster - all from just drawing a line. You could also select that wall and change it to a completely different wall type. If you select a window tool and click on the wall it will cut in a window with full spec.
This wall and window is now available to create auto elevations, sections, scheduling, 3D renderings etc.
I can also automatically show this wall in plan view in any number of ways. Just a bold outline and fill for presentations, show each leaf for construction, and light outline for backgrounds for electrical and service layouts. Automatically.
There is so much that is automated allowing you to spend time on things like rendering etc.
I say this only to illustrate. You need to do some serious reading and watching to understand the process but hopefully you get the power. Lines and circles are out. (actually I still use lines etc to indicate something that I don't need to model.
Take a few weeks and set time aside to watch and then play to reinforce. Don't commit to a project too soon and not one you have a deadline on. Perhaps your own project that is down the track. I always struggle to spend time on projects that dont have a purpose. The nice thing about ACA as opposed to Revit is you are in a familiar environment. If you get stuck and have a deadline you can always revert to Autocad 2d. But that is also a trap. With Revit there is only the way of modelling. Many using ACA don't test it's real power because they don't learn it's full potential and they fall back to 2d habits.
BEWARE of customising!!! Too many (me included) customise to suit themselves and make things a lot harder. I now customise but because I now know what to touch and what to accept and leave alone. I gave myself such headaches in early days.
I found archidigm.com an excellent teaching resource.
http://www.archidigm.com/classroom/index.htm
and in particular
http://www.archidigm.com/classroom/adt_4_development_guide/adt_5_dg_cover.htm
If you are on sub you have access to Autodesk Virtual University and the back catalogue of awesome videos from masters.
There is little taught these days but the back cat. is worth viewing.
http://architects-desktop.blogspot.com/ (have to sort thru Revit and ACA posts but lots of excellent articles.)
my own blog
http://ausaca.blogspot.com/
I have my own rants. I think the OOTB process is convoluted for residential projects and I have my own process so beware of that when watching my stuff. I'd suggest learn the OOTB method first so you understand it.
www.ausaca.blogspot.com
Do you know all about the Roof Object? Learn it's secrets
http://ausaca.blogspot.com.au/p/roof-object-video-links.html